In order to analyze these replication proteins and cellular signaling pathways, we use a variety of techniques such as: co-immunoprecipitation, a modified ELISA technique, fluorescence (cross) correlation spectroscopy (FC(C)S), and fluorescence recovery after photobleaching (FRAP).

In living cells we have expressed fusion proteins with the green fluorescent protein (GFP) and carried out FCS, FCCS and FRAP.

The human polyoma viruses BKV and JCV are small, non-enveloped, icosahedral viruses and their genomes are organized in circular double-stranded DNA.

In contrast, the closely related JCV causes Progressive Multifocal Leukoencephalopathy (PML) a demyelating disease of brain in immunosuppressed humans such as AIDS patients (Fig 2A). The viral replication is usually restricted to glial cells in these patients (Fig 2B).

Recently, JCV received significant attention since PML was found to be a side effect of medical treatments for arthritis, Crohn’s Disease and multiple sclerosis.

The risk of developing PML is about 1/500 for patients treated with “Tysabri” (a blockbuster drug to treat MS) but it rises to 1/85 in case of additional risk factors.

Therapies to inhibit BKV and JCV replication are still lacking. Therefore, to study the life cycle of these viruses we have established cell-free BKV and JCV DNA replication systems.